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Applying social cognitive theory to examine farmer migration in response to groundwater salinity: The case of Qaenat, Iran
Get PDFAdverse climatic conditions and excessive groundwater extraction have jeopardized agriculture and water resources, caused the salinization of agricultural wells and prompted widespread rural-to-urban migration. To develop effective decentralization policies, it is crucial to analyze farmers' migration behavior in response to increasing water salinity. This study applies the Extended Social Cognitive Theory (ESCT) to explore these dynamics. This study employs a descriptive-survey research method, with the statistical population comprising farmers in Qaenat County, South Khorasan Province. A proportional random sample of 300 farmers was selected and surveyed using a researcher-developed questionnaire. The validity of the questionnaire was confirmed through expert opinions, while its reliability was assessed using Cronbach's alpha coefficient, ranging from 0.6 to 0.95. The Structural Equation Modeling (SEM) analysis revealed that the perception of others' behavior (POB), attitudes, and perceived barriers significantly predict the willingness to adapt to water salinity through both technical and non-technical methods. Furthermore, the findings revealed that the ESCT accounted for 48.4 % of the variance in farmers' migration intentions and 29.5 % of the variance in their actual migration behavior. Among the examined factors, perceived behavior of others, attitudes, and social capital emerged as key determinants of migration behavior, while moral norms exerted the strongest influence on migration intentions. These results underscore the critical role of socio-cognitive variables in shaping adaptive responses to the challenges posed by water salinity. Future research could apply various behavioral models to investigate both technical and non-technical adaptation strategies, offering a more comprehensive understanding of how individuals respond to environmental challenges across different contexts
Uncovering the economic potential of sustainable aviation fuel production pathways: A meta-analysis of techno-economic studies
Get PDFSustainable aviation fuel (SAF) is a key component for the defossilization of the aviation sector. The economic feasibility of SAF production is typically evaluated through techno-economic assessments (TEA), with the Minimum Jet Fuel Selling Price (MJSP) serving as the key economic performance indicator. Comparing MJSP values across different SAF pathways is challenging and potentially misleading due to differences in modelling assumptions, estimation methods for key variables, and their underlying relationships. This study aims to contribute to a more comprehensive understanding of the economic feasibility of four prominent SAF pathways: Hydroprocessed Esters and Fatty Acids (HEFA), Pyrolysis-to-Jet (PTJ), Alcohol-to-Jet (ATJ), and Fischer-Tropsch (FT). We employed qualitative and quantitative methods, including meta-analysis and variable harmonization, to analyze a wide range of TEA studies from the literature and investigate the factors contributing to MJSP variation for these pathways. Our findings reveal that feedstock cost is a primary driver of MJSP variability across all pathways. Moreover, regression and harmonization analyses uncovered complex interdependencies among economic variables often underexplored in individual TEAs. Key sources of MJSP variability include methodological differences in by-product credit valuation, process design choices, capital cost estimation approaches, and financial assumptions. Recognizing and addressing these factors offers strategic opportunities to improve the techno-economic performance and comparability of SAF pathways. Notably, the PTJ pathway emerged as a promising alternative for non-food feedstocks, and all pathways demonstrated improved economic outcomes when integrated with existing industrial infrastructure. The analytical findings of this study provide a robust empirical foundation that can be leveraged by future studies aimed at policy analysis, as well as for project budgeting and investment decisions in sustainable aviation fuels
The case for a clean cooking green bank
Get PDFThe socio-economic and climate benefits of a transition to clean fuels and technology for cooking are gaining prominence on the global policy agenda. However, investment volumes fall critically short of those required to achieve Sustainable Development Goal 7's universal clean cooking access target, while available forms of finance often do not match demand. We investigated the value in creating a specialised public bank, modelled on green state investment banks, to address the clean cooking investment challenge. In so doing, we introduced the green bank concept to the academic literature on clean cooking and provided original data and analysis. Expert interviews revealed a desire for public banks to assume greater risk in their financing activities in clean cooking markets, and to adopt a broader array of financial instruments and structures. Interviewees also recommended that public banks act as pathfinders and first movers in these markets, play a more prominent role in market building, and educate and organise the aggregate funding group. These attributes displayed notable similarities with the roles historically undertaken by green banks. Our findings suggested that a dedicated public bank for clean cooking, modelled on green banks, would be additional to the sector and potentially play a catalytic role in leveraging private investment
Science–policy–practice insights for compound and multi‐hazard risks
Get PDFWhen multiple weather‐driven hazards such as heatwaves, droughts, storms or floods occur simultaneously or consecutively, their impacts on society and the environment can compound. Despite recent advances in compound event research, risk assessments by practitioners and policymakers remain predominantly single‐hazard focused. This is largely due to traditional siloed approaches that assess and manage natural hazards. Hence, there is a need to adopt a more ‘multi‐hazard approach’ to managing compound events in practice. This paper summarizes discussions from a 2‐day workshop, held in Glasgow in January 2023, which brought together scientists, practitioners and policymakers to: (1) exchange a shared understanding of the concepts of compound and multi‐hazard events; (2) learn from examples of science–policy–practice integration from both the single hazard and multi‐hazard domains; and (3) explore how success stories could be used to improve the management of compound events and multi‐hazard risks. Key themes discussed during the workshop included developing a common language, promoting knowledge co‐production, fostering science–policy–practice integration, addressing complexity, utilising case studies for improved communication and centralising information for informed research, tools and frameworks. By bringing together experts from science, policy and practice, this workshop has highlighted ways to quantify compound and multi‐hazard risks and synergistically incorporate them into policy and practice to enhance risk management
Investigating carbon and nitrogen conservation in reported CMIP6 Earth system model data
Get PDFReliable, robust, and consistent data are essential foundations for analysis of carbon cycle feedbacks. Here, we consider the data from multiple Earth system models (ESMs) participating in the Coupled Model Intercomparison Project Phase 6 (CMIP6). We identify a mass conservation issue in the reported carbon and nitrogen data, with a few exceptions for specific models and reporting levels. The accumulated mass imbalance in the reported data can amount to hundreds of gigatons of carbon or nitrogen by the end of the simulated period, largely exceeding the total carbon–nitrogen pool size changes over the same period. Nitrogen mass imbalance is evident across all reported organic and inorganic pools, with mineral nitrogen exhibiting the most significant cumulative mass imbalance. Due to a lack of detail in the reported data, we cannot uniquely identify the cause of this imbalance. However, we postulate that the carbon mass imbalance primarily arises from missing fluxes in the reported data and inconsistencies between these data and the definitions provided by the C4MIP protocol (e.g., land-use and fire emissions), rather than from an underlying mass conservation issue in the models themselves. Our findings suggest that future CMIP reporting protocols should consider incorporating mass conservation into their data validation processes so that such issues are caught before users have to deal with them, rather than forcing all users to handle this issue in their own way. In addition, attention from model groups to the detailed diagnostic request and definitions, along with their own quality control, will also help to avoid such issues in future. Given that no additional CMIP6 data are currently being published and none are expected in the future, we recommend that data users that rely on a closed carbon–nitrogen cycle address potential flux imbalances by using the workarounds provided in this study
Human Population Growth
No full textThe sheer number of population has been for long the main (and only) consideration about human population growth in ecological engineering and in other fields that are reflecting on the sustainability of life systems on earth. However, with the availability of data on human behavior, we now know that what is important for the future is not only how many people there will be but what they will do in their everyday life which could impact the life systems surrounding them and how equipped they will be to face emerging challenges. Nevertheless, the challenges exist, and in the coming decades, the survival and well-being of humans and the security of environmental resources that support human existence will continue to be challenged by rapid population growth, particularly in less developed regions that are the main contributors to world population, i.e., Sub-Saharan Africa and Southern Asia. While the number of humans is likely to peak within the next hundred years, still a few additional billion people will live on earth. Ecological engineering and systems analysis will be crucial in comprehending the complexities associated with human population growth and in devising strategies to address the challenges stemming from human behavior within ecological systems
Towards net-zero emissions in global residential heating and cooling: a global scenario analysis
Get PDFAccounting for 21% of global greenhouse gas (GHG) emissions, buildings play a crucial role in climate change mitigation. Demand-side policies offer large energy and GHG emission reduction potentials. The effects of broader sectoral policies at the global level beyond energy efficiency improvements, including sufficiency and structural changes, and their interaction with cross-sectoral climate policies are, however, still unclear. Here, we assess a comprehensive set of scenarios to reduce residential space heating and cooling emissions towards net-zero targets. We find that activity reductions, fuel shifts, and technological improvements can reduce current global residential space heating and cooling CO 2 emissions by 57% relative to a reference scenario in 2050. Combining these demand-side policies and stringent climate policies could result in CO 2 emission reductions up to 91% relative to the reference scenario in 2050. Neutralizing residual direct CO 2 emissions would require additional interventions targeting fossil fuel-based heating systems still in use in 2050
Material and energy use in Norway's residential building archetypes
No full textBuildings require substantial amounts of resources, as both construction materials and operational energy. In Norway, as buildings become more energy efficient due to advancements in construction, technology, and stricter regulations, the relative impact of construction and maintenance materials rises. However, there is a lack of comprehensive data on construction and material use, and consequently, their embodied emissions. While some studies explored the environmental impacts of Norwegian buildings, they often either focus on case‐study buildings or only the operational emissions, due to limited data on embodied emissions; others rely on inconsistent statistical correlations between energy use and material composition. Bottom‐up physics‐based building archetypes offer a solution to fill this gap by providing structured data on energy use and material composition. This paper, therefore, introduces 21 archetypes of Norwegian residential buildings, categorized into three typologies and seven construction cohorts. Dynamic energy simulations were conducted, using DesignBuilder, for estimating space heating consumption, combined with the BuildME Python package for material estimation and aggregation. We found that load‐bearing components drive building's material intensity, especially in wooden buildings with basements. Post‐1991 multi‐family houses (MFHs) have lower material intensity than single‐family houses (SFHs) and apartment blocks (ABs), though ABs outperform them by lower space heating demand. Substitution of concrete slabs by wood and increasing occupancy to MFH's level can reduce the material intensity of ABs and SFHs, respectively. By establishing integrated energy and material demand models, archetypes provide a representative and scalable basis for further assessment of building stock's resource use, renovation impacts, and environmental studies
Development and validation of a gridded emissions inventory for HFC-134a in China
Get PDF1,1,1,2-Tetrafluoroethane (HFC-134a), a potent greenhouse gas, breaks down to form trifluoroacetic acid (TFA). Lack of its gridded emissions inventories makes it difficult to analyze the spatial distribution of emissions. This study developed a framework for national and gridded HFC-134a bank and emission calculations, validation and environmental impact assessments. Within this framework, we used production and consumption data along with emission factors to compile a gridded inventory for China. The results reveal an increase in national HFC-134a emissions, from 0.1 kt yr−1 in 1995 to 48 kt yr−1 in 2020, with banks also increasing from 0.9 to 301 kt. Guangdong, Jiangsu, and Shandong provinces showed the largest cumulative emissions, totaling 98 kt between 1995 and 2020, representing 28% of HFC-134a national emissions. A Lagrangian dispersion model, in conjunction with atmospheric observations, was used to validate the gridded inventory, where the simulations based on the gridded inventory were in reasonable agreement with the observations. A carbon–neutral (CN) scenario was developed to project future emissions. The adoption of HFO-1234yf and R-513A as substitutes for HFC-134a is projected to cause an additional 701 kt of cumulative TFA formation potential between 1995 and 2060, on top of the 3825 kt projected under the Kigali Amendment scenario